1. Field of the Invention
The present invention relates to a chip resistor and to a method for manufacturing a chip resistor.
2. Description of the Related Art
A conventional chip resistor is described in JP-A-2007-49207, for example. The chip resistor disclosed in this document includes a resistor element and a pair of electrodes provided on a surface of the resistor element. The paired electrodes are insulated from each other and directly bonded to the surface of the resistor element. An overcoat layer for protecting the resistor element is formed on the surface of the resistor element which is opposite from the surface formed with the electrodes. By making a resistor element using a metal plate of an alloy having a low temperature coefficient of resistance (TCR), a chip resistor having an extremely low resistance of a few milliohms (mΩ) in addition to a low TCR is obtained. To achieve a higher resistance of e.g. several tens to hundreds of milliohms, the width of the resistor element is reduced partially or part of the resistor element is removed by laser trimming or etching.
In the conventional chip resistor, however, the resistor element itself is made of a relatively thin metal plate, and the overcoat layer does not have a sufficient thickness to support the resistor element and the electrodes. Thus, when the resistor element is made narrow or partially removed, the sufficient strength to support the electrodes is not provided by the metal plate and the overcoat layer. Further, when current is applied, the resistor element is heated. In the conventional structure, the heat is trapped in e.g. the narrow portion and cannot be dissipated efficiently.